Erratic Idling On 1.8se

[Holmesy]

I am wondering if somebody can please give me a bit of advice about the following fault?

CAR:- 99 Toyota Avensis 1.8SE Manual 7A-FE

Until recently the car was running fine 30 mpg, starting first time etc, then I had some work undertaken on the gearbox and since then, the car starts and idles at 2000rpm (sometimes higher) on auto-choke then idles at 600-900 revs (anywhere between these figures).

When I press the elec window button or heater or heated screen the revs drop to sub 500rpm and the engine wants to cut out?

My main worry is the MPG which has halved, normally I would mind but when I throw £30 of juice in I would expect to get more than 150 miles?

The car is still under warranty as I have only had it 4 weeks so it looks as though it needs to go back.

Any ideas?

Many thanks

Ian :D

[Holmesy]

Update:-

I recently put a further £20 worth of fuel in my car and from those 6 gallons got 190 miles?

The car is still running sluggish and there seems to be a "missfire" of some sort?

Does it sound like the ECU? I hope not...

Cheers

Ian

[Holmesy]

Please????

The car is idling on start up at 2000 rpm, then when warm goes down to 600 rpm.

It nearly cuts out when I put the fan, heated window or electric windows on??

Any advice is appreciated.

Thanks

[nick007]

a idearmay be that on the inlet manifold close to the head on the os by dipstick is a secondry butterfly for the lean burn system and this may have come disconnected

[jamesholden]

Well 2000 down to 600 isn't that major, next door had a similar problem with her car where when you put stuff on it would cut out, it turned out to be a dead cell in the Battery causing a voltage drop so all electrics would stop therefore cutting out - perhaps get that bench tested at Halfords or somewhere to see if they think it's knackered.

[sjrainsford]

Mine revs to nearly 2000rpm when started cold, and gradually eases it's way down to 600rpm ish, but runs very smooth at that point. However when on cold start function it does become slightly unstable.

However, I had trouble like you're having when I found out that the spark plugs that were fitted in the service before I had it, were the wrong type - well they were normal ones. The ends had burnt away!

Also, have a good check round the vacuum hoses and see if there isn't a split one - or one just pulled off.

However, the injection system should try to counteract any load on the engine. A good one to try, is put the handbrake on with the engine running warm. Then stick it in second gear or whatever and slowly let the clutch out to simulate load on the engine thus slowing it down. When the clutch begins to drag the engine down, leave it where it is and see if the engine tries to bring itself upto speed again. Then when depress the clutch again, the engine should over rev momentarily and stabilize back to 600rpm.

Let us know what happens. There may be a prob with the throttle advance mechanism

[Holmesy]

a idearmay be that on the inlet manifold close to the head on the os by dipstick is a secondry butterfly for the lean burn system and this may have come disconnected

Nick,

Cant seem to find the sensor you where talking about?

have you got a link / pic you could show me where abouts the "secondary butterfly" is.. please

regards

[yaristpot]

Stupid question..... if its new to you and they have worked on the gearbox then why not take it back???

[Starensis]

Usual problem is that vacuum hose has become disconnected from your idle-up sensor.

This sensor is located on the bulkhead & has both electrical & hose connections. From past experience, this hose usually comes adrift from sensor after a gbox has been removed/dropped, thus causing low idling speeds during loading.

Sensor detects engine vacuum loss due to loading & tells the ECU to increase idle speed.

Check it out! One way to tell if it's operating is to turn you steering wheel with engine warm, at idle. You should hear/detect an increase of engine speed.

Hope this helps.